The change of the capabilities of computers is another factor. Now it is easy to get email via a mobile phone and therefore interact with and observe machines. Before this was only possible at work or at home. And, asks van Splunter, how acceptable is it to turn off your mobile phone or not checking your email? In some environments it might not be acceptable. There can be a need to witness.
On the other hand witnessing might be fun. When a system keeps adapting in a dynamic way, this might be interesting to witness even though looking at it might not give new or useful information. It is just the observation of the dynamics, which is fun. If there is an interesting rhythm to observe, then it becomes fun to observe it, even more so when you can also have some interaction affecting this rhythm.